Photoinactivation of functional photosystem II and D1-protein synthesis in vivo are independent of the modulation of the photosynthetic apparatus by growth irradiance

Planta ◽  
1996 ◽  
Vol 198 (2) ◽  
Author(s):  
Youn-Il Park ◽  
JanM. Anderson ◽  
WahSoon Chow
Keyword(s):  
Protein Synthesis ◽  
Photosystem Ii ◽  
Photosynthetic Apparatus ◽  
D1 Protein ◽  
Growth Irradiance

scholarly journals The role of inactive photosystem–II–mediated quenching in a last–ditch community defence against high light stress in vivo

2002 ◽  
Vol 357 (1426) ◽  
pp. 1441-1450 ◽  
Author(s):  
Wah Soon Chow ◽  
Hae–Youn Lee ◽  
Youn–Il Park ◽  
Yong–Mok Park ◽  
Yong–Nam Hong ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Light Stress ◽  
Extreme Environments ◽  
Photosynthetic Apparatus ◽  
Optimal Operation ◽  
Residual Fraction ◽  
Photosynthetic Membrane ◽  
Number Of Factors ◽  
Inactive Photosystem Ii

Photoinactivation of photosystem II (PSII), the light–induced loss of ability to evolve oxygen, is an inevitable event during normal photosynthesis, exacerbated by saturating light but counteracted by repair via new protein synthesis. The photoinactivation of PSII is dependent on the dosage of light: in the absence of repair, typically one PSII is photoinactivated per 10 7 photons, although the exact quantum yield of photoinactivation is modulated by a number of factors, and decreases as fewer active PSII targets are available. PSII complexes initially appear to be photoinactivated independently; however, when less than 30% functional PSII complexes remain, they seem to be protected by strongly dissipative PSII reaction centres in several plant species examined so far, a mechanism which we term ‘inactive PSII–mediated quenching‘. This mechanism appears to require a pH gradient across the photosynthetic membrane for its optimal operation. The residual fraction of functional PSII complexes may, in turn, aid in the recovery of photoinactivated PSII complexes when conditions become less severe. This mechanism may be important for the photosynthetic apparatus in extreme environments such as those experienced by over–wintering evergreen plants, desert plants exposed to drought and full sunlight and shade plants in sustained sunlight.

Two mechanisms of recovery from photoinhibition in vivo: Reactivation of photosystem II related and unrelated to D1-protein turnover

Planta ◽  
1994 ◽  
Vol 194 (1) ◽  
Author(s):  
Joachim Leitsch ◽  
Barbara Schnettger ◽  
Christa Critchley ◽  
G.Heinrich Krause
Keyword(s):  
Photosystem Ii ◽  
Protein Turnover ◽  
D1 Protein

Regulation of D1-protein degradation during photoinhibition of photosystem II in vivo: Phosphorylation of the D1 protein in various plant groups

Planta ◽  
1995 ◽  
Vol 195 (3) ◽  
Author(s):  
Eevi Rintam�ki ◽  
Riitta Salo ◽  
Elina Lehtonen ◽  
Eva-Mari Aro
Keyword(s):  
Photosystem Ii ◽  
Protein Degradation ◽  
D1 Protein ◽  
Plant Groups

Quality control of Photosystem II under light stress – turnover of aggregates of the D1 protein in vivo

2005 ◽  
Vol 84 (1-3) ◽  
pp. 29-33 ◽  
Author(s):  
Satoshi Ohira ◽  
Noriko Morita ◽  
Hwa-Jin Suh ◽  
Jin Jung ◽  
Yasusi Yamamoto
Keyword(s):  
Quality Control ◽  
Photosystem Ii ◽  
Light Stress ◽  
D1 Protein ◽  
Control Of Photosystem Ii

SO2 Injury in Intact Leaves, as Detected by Chlorophyll Fluorescence

1988 ◽  
Vol 43 (3-4) ◽  
pp. 269-274 ◽  
Author(s):  
Wolfgang Schmidt ◽  
Ulrich Schreiber ◽  
Wolfgang Urbach
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Calvin Cycle ◽  
Photosynthetic Apparatus ◽  
Enzymatic Reactions ◽  
Decay Kinetics ◽  
Saturation Pulse ◽  
Induction Kinetics ◽  
Fluorescence Measurements

The effects of short-time fumigation (0-60 min) of intact spinach leaves with SO2 (2 ppm) on the photosynthetic apparatus were investigated. A rather high SO2 concentration was applied to monitor immediate effects on the fluorescence behaviour with the influence of repair processes or secondary types of damage being minimized. Three different types of in vivo chlorophyll fluorescence measurements were used: Rapid induction kinetics (Kautsky effect), slow induction kinetics with repetitive application of saturation pulses (saturation pulse method), and decay kinetics following a single turnover saturating flash. The slow induction kinetics with repetitive application of saturation pulses reacts in the most sensitive way indicating a primary damage at the level of the enzymatic reactions of the Calvin cycle. It is suggested that stromal acidification upon SO2 uptake interferes with light activation of Calvin cycle enzymes. With longer fumigation times also damage at the level of photosystem II becomes apparent: A decrease in variable fluorescence yield reflects a lowering of photosystem II quantum yield, and the slowing down of fluorescence relaxation kinetics reveals an effect on the secondary electron transport from Qᴀ to Qв. The detrimental effects of SO2 depend to a great extent on the application of light during fumigation. Besides a light requirement for SO2 uptake by stomata opening also the possibility of photoinhibitory damage is discussed. The susceptibility of leaves to photoinhibition may increase with a lowering of Calvin cycle activity by SO2.

scholarly journals Structural and functional dynamics of plant photosystem II

2002 ◽  
Vol 357 (1426) ◽  
pp. 1421-1430 ◽  
Author(s):  
Jan M. Anderson ◽  
W. S. Chow
Keyword(s):  
Photosystem Ii ◽  
Singlet Oxygen ◽  
Membrane Surface ◽  
D1 Protein ◽  
Indirect Evidence ◽  
Light Level ◽  
Energy Utilization ◽  
Direct Access ◽  
Unique Problem

Given the unique problem of the extremely high potential of the oxidant P + 680 that is required to oxidize water to oxygen, the photoinactivation of photosystem II in vivo is inevitable, despite many photoprotective strategies. There is, however, a robustness of photosystem II, which depends partly on the highly dynamic compositional and structural heterogeneity of the cycle between functional and non–functional photosystem II complexes in response to light level. This coordinated regulation involves photon usage (energy utilization in photochemistry) and excess energy dissipation as heat, photoprotection by many molecular strategies, photoinactivation followed by photon damage and ultimately the D1 protein dynamics involved in the photosystem II repair cycle. Compelling, though indirect evidence suggests that the radical pair P + 680 Pheo – in functional PSII should be protected from oxygen. By analogy to the tentative oxygen channel of cytochrome c oxidase, oxygen may be liberated from the two water molecules bound to the catalytic site of the Mn cluster, via a specific pathway to the membrane surface. The function of the proposed oxygen pathway is to prevent O 2 from having direct access to P + 680 Pheo – and prevent the generation of singlet oxygen via the triplet–P 680 state in functional photosytem IIs. Only when the, as yet unidentified, potential trigger with a fateful first oxidative step destroys oxygen evolution, will the ensuing cascade of structural perturbations of photosystem II destroy the proposed oxygen, water and proton pathways. Then oxygen has direct access to P + 680 Pheo – , singlet oxygen will be produced and may successively oxidize specific amino acids of the phosphorylated D1 protein of photosystem II dimers that are confined to appressed granal domains, thereby targeting D1 protein for eventual degradation and replacement in non–appressed thylakoid domains.

Amino Acid Substitutions in the D1 Protein of Photosystem II Affect QB-Stabilization and Accelerate Turnover of D1

1990 ◽  
Vol 45 (5) ◽  
pp. 402-407 ◽  
Author(s):  
Nir Ohad ◽  
Dekel Amir-Shapira ◽  
Hiroyuki Koike ◽  
Yorinao Inoue ◽  
Itzhak Ohad ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
D1 Protein ◽  
Genetically Engineered ◽  
Close Link ◽  
Synechococcus Pcc 7942 ◽  
Temperature Downshift ◽  
The Stability ◽  
Pcc 7942 ◽  
Isogenic Strains

Abstract Isogenic strains of Synechococcus PCC 7942 were genetically engineered so that copy I of the gene psbA was mutated at specific sites. These mutations resulted in replacements of Ser 264 by Gly or Ala and of Phe 255 by Tyr or Leu in the D1 protein. The mutants were resistant to herbicides inhibiting electron transfer in photosystem II. All mutants exhibited alterations in the stability of QB- as demonstrated by a temperature downshift, to various extents, of the in vivo thermoluminescence emission. Measurements of the light-dependent turnover of D1 showed a marked decrease in the t 1/2 of this protein in the mutants as compared to wild-type, under low to medium light intensities. A correlation was found between the degree of pertur­ bation in the QB- stability and the rate of acceleration in the turnover of D1. These data pro­ vide a direct evidence for the overlapping binding sites for the plastoquinone B and herbicides in the D1 protein. In addition these data indicate a close link between QB- destabilization in reaction center II and the mechanism controlling the light-dependent turnover of D1. Based on these results and previous work we suggest that destabilization of the semireduced quinone, facilitates a light-induced damage in D1 which triggers its degradation.

Sign in / Sign up

Export Citation Format

Share Document